The usual answer to that is you keep the money in the business entity while paying yourself a minimal salary. You spend it on business expenses (commonly stuff like travel or a vehicle or computer hardware, with some semi-plausible fig-leaf of business use), or take it as long-term capital gains later on.

The other answer that could fit the premise is a solo 401k, for the higher pre-tax contribution limit than a standard employer 401k.

I'd be surprised if there was really anything substantial besides those.